Description of functions
Copyright IXXAT Automation GmbH
11
CANio 500 Quickstart Manual, version 1.3
current, first the error of the overcurrent must be eliminated or the short-circuit
removed. Then the fuse switches on again automatically after a few seconds.
The CANio 500 is protected by diodes against reverse polarity and return cur-
rents.
4.4
Digital inputs
The CANio 500 has 4 digital inputs and an additional digital input on the power
supply connector, which can be monitored via a CAN message. More infor-
mation is given in chapter 5.1.6.
4.4.1 Digital inputs 1-4
The digital inputs (1-4) are equipped with an adjustable threshold.
The external reference voltage VREF_IN is freely selectable from 0 to 60 V.
The internal circuit enables a switching threshold at 50 % of the external refer-
ence voltage VREF_IN. This means, for example, that at a voltage VREF_IN
of 12 V the switching threshold is approximately 6V. A hysteresis of approxi-
mately 50 mV ensures trouble-free operation of the switching threshold. The
reference voltage VREF_IN is used for all 4 digital inputs simultaneously. The
reference voltage VREF_IN and the digital inputs are protected for voltages of
more than 60 V.
A reference voltage VREF_OUT is available on the digital connector, which
corresponds to the power supply PWR(+). This reference input VREF_OUT
can be connected to the external reference input VREF_IN via a bridge on the
connector.
The digital inputs have a low-pass filter to minimize disturbances. The filter
used is a simple grade 1 filter with an RC circuit set to a cut-off frequency
3 dB
of approximately 1 kHz.
4.4.2 Additional digital input on connector (X1)
The additional digital input on the power supply connector (X1) has a fixed
threshold of approx. 7 V and can be used, for example, in the automotive sec-
tor for the monitoring of terminal 15.
4.5
Analog outputs
Four channels are available in the CANio 500 with a resolution of 12 bits on
the analog output. The analog outputs can be set with CAN messages. More
information is given in chapters 5.1.5
The internal reference voltage source and the DAC itself have an accuracy of
0.2 %. The output current is limited to 20 mA. If the current is exceeded, the
corresponding output is switched off and an emergency message is sent (see
5.1.12).